Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

103 theme 3 > principles of blood transfusions > Flashcards

principles of blood transfusions Flashcards

1
Q

who had the first transfusion

A

Pope Innocent VIII (1492) was transfused the blood of 3 boys on his deathbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

who did a dog to dog transfusion

A

Richard Lower 1665

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what were other attempts at blood transfusion

A

Jean-Baptiste 1667 (sheep to human, patent died so practice abandoned for 150 years)
James Blundell 1818 did a human to human transfusion, successful treatment of postpartum haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

who is Karl Landsteiner

A

recognised issue of blood incompatibility
identified agglutinins in blood, distinguished main blood groups
father of transfusion medicine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are blood transfusion milestones (since WW1)

A 
1921	First Red Cross Voluntary Donation
1939-45	Voluntary donations
1937	First UK Blood Bank
1975	Plastic blood bags replace glass
1986	HIV testing
1991	Hepatitis C testing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are blood groups

A

Red cells have antigens on surface
plasma may contain antibodies to these antigens
can cause reactions - sometimes fatal
fundamental problem in blood transfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the ABO system

A 
A antigen
B antigen 
AB antigen 
No antigen 
A, B, AB, O type
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are agglutinins

A

Naturally occurring (pentameric) IgM antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are ABO antibodies

A

Antibodies to ABO antigens occur naturally due to cross reactivity with gut bacterial antigens
These are IgM (pentameric) antibodies able to fix complement and cause red cell lysis
eg A antigen has anti-B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are ABO antibodies

A

Antibodies to ABO antigens occur naturally due to cross reactivity with gut bacterial antigens
These are IgM (pentameric) antibodies able to fix complement and cause red cell lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where are blood antigens and antibodies found

A

Blood group A, A antigens on surface of RBCs and B antibodies in Blood plasma
Group B opposite
AB - both surface antigens and no ABs in plasma
Group O- no surface antigens but both antibodies in blood plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how can blood group be found

A

agglutination reactions

antigen present in specimen will bind to antibody and form visible aggregates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is blood cross matching

A

forward (antibodies against blood group) and reverse (A/B/O cells against blood type) to see agglutination reaction
eg A forward - react with Anti-B and reverse - A and O cell reactions
anti D reaction - negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the ABO compatibilities

A

AB - give to AB and receive AB, A, B, O
A - give to A, AB and receive A and O
B opposite of A
O - give to AB, A, B, O and receIve O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are blood group frequencies

A

O 46% genotype OO
A 42% AA/AO
B 9% BB/BO
AB 3% AB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is blood grouping done with gel cards

A 
blood at top of the column = agglutination reaction
blood at bottom = no reaction
the control should be negative
Cells vs Anti-A, B and D
Anti D (+ve or -ve type)
Control cells vs plasma
Plasma vs gp A cells and gp B cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does a lab do when sent a blood sample

A

1) Test the ABO group of the red cells

2) Screen the plasma for “atypical antibodies”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are a typical antibodies

A

arise due to sensitisation with foreign red cell antigens caused either by previous blood transfusion or by pregnancy
Atypical antibodies can cause blood transfusion reactions if the patient is transfused with incompatible blood in the future

19
Q

what is the Coombs test

A

anti-globulin test
It uses anti-immunoglobulin antibody to agglutinate red cells
There are two types: direct (DAT) and indirect (IAT)

20
Q

what is the DAT and IAT

A

The DAT =red cells coated with antibody
It is positive after a transfusion reaction and in HDN
It is also positive in autoimmune haemolytic anaemia

The IAT is used in the lab for testing blood group antigens
It can tell us if a patient is positive for Rhesus and other blood groups

21
Q

what is the Rhesus system

A

Rh positive people cannot develop antibodies

But 15% of people are Rh negative

22
Q

what is rhesus sensitisation

A

Rh neg people can develop antibodies if they are transfused with Rh pos blood or are pregnant with a Rh pos baby
antibody generated is IgG type
most important antigen is RhD

23
Q

What are the issues of RhD sensitisation

A

those who develop antibodies cannot be given +ve blood
if Rh neg mother has Rh pos baby then antibodies may harm baby
haemolytic disease of the newborn
Anaemia, jaundice and kernicterus (brain damage)

24
Q

How can HDN be prevented

A

ABO and Rh blood group check at 12 weeks
Rh-ve get Anti-D antibody injection at 28 and 34 weeks
if already sensitised then monitor via trans-cranial doppler scan and intra-uterine transitions if sings of anaemia

25
Q

what is in a bag of donated blood

A 
Red cells
Buffy coat (white cells, platelets)
Plasma (albumin,
gamma globulins,
coagulation factors)
Water, electrolytes, additives
26
Q

What does a junior doctor need to know about blood transfusion?

A 
When to give a blood transfusion
What type of transfusion to give
How to request blood transfusion
How to monitor a blood transfusion
What are the problems and complications
27
Q

what is apheresis

A

remove particular substance from blood, main volume returned to body

28
Q

when should a blood transfusion be given

A 
Severe acute blood loss (Severe trauma 
Massive GI or
Obstetric blood loss)
Elective surgery associated with significant blood loss
Medical transfusions
Cancer, chemotherapy, renal failure
Anaemia
Bone marrow failure 
Haemoglobinopathy
29
Q

what are blood components of transfusion

A

Red cells
Platelets
Fresh frozen plasma
Cryoprecipitate (fibrinogen)

30
Q

what are plasma derivatives (pooled products) of transfusion

A

Immunoglobulin
Coagulation factors (e.g., Octaplex)
Albumin

31
Q

what are other types of transfusions

A 
Cell salvage (rarely done during operations)
Autologous transfusion (very rarely done)
Blood and plasma derivatives
32
Q

what is required for pre transfusion testing

A

Informed consent
Record reason for transfusion in notes
Sampler – ask patient their name and check ID on wristband
Make sure the patient gets the “Right blood at the Right time”
Most errors are caused by failure to follow procedures

33
Q

what info is requested for transfusion

A 
ID (surname, name, DOB, hospital number)
Blood group
Previous transfusions
Reason for request
Type of blood product and amount
Special requests
When and where
Doctor (audit trail)
34
Q

what is the sample info

A

ID
Signature of phlebotomist (audit trail)
Date
Do not use addressograph labels

35
Q

what is compatibility testing

A

Establish ABO and Rh group
Check for atypical antibodies in patient serum
Select donor blood
Compatibility testing between donor cells and patient serum
Issue blood with appropriate labels

36
Q

what is emergency blood

A

O negative
Immediate (5 mins)
major haemorrhage protocol

37
Q

how available is group compatible blood

A

same group at patient

10-15 mins

38
Q

how available is fully screened and cross matched blood

A

Approximately 45 minutes (but maybe hours if antibody found)

39
Q

what are blood transfusion reactions

A

Febrile non-haemolytic reactions
Fluid overload
Anaphylaxis and severe allergic reactions
Minor allergic reactions
Delayed transfusion reactions
TRALI (transfusion related acute lung injury)

40
Q

what are major ABO incompatibilities

A

Acute renal failure
Disseminated intravascular coagulation
Death

41
Q

what are transfusion transmitted infections

A 
Bacterial infections
(syphilis
pyogenic infections
contamination infections (pseudomonas))
Viral infections
hepatitis (B,C)
HIV
Others - HTLV, CMV
Emerging - West Nile virus
Malaria
vCJD
42
Q

how is fluid overload a physiological hazard

A

infused too quickly
transfuse 1 unit over 4 hrs if elderly or evidence of heart failure (1 unit, 2 hours, younger patients)
can cause acute pulmonary oedema
treat with diuretics (frusemide) to remove fluid

43
Q

how is iron overload a physiological hazard

A

haemosiderosis = iron overload
iron deposited in tissues (liver, heart, pancreas, skin)
can treat by iron chelation

103 theme 3 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions